1. Technical Field
The present invention generally relates to a robot controlled sealant dispenser for use in a manufacturing environment. More particularly, the present invention is directed to a robot controlled sealant dispensing system which allows all six axes of the robotic manipulator to be utilized during the sealant dispensing and application process.
2. Discussion
Robot based manufacturing continues to find new applications as the technology for controlling and implementing robot based systems is improved. One particular use for robot based systems is the dispensing and application of sealant to individual parts to be assembled, such as those parts found in an automotive assembly facility. A variety of systems have been developed to implement this robot based automation technique. One such application involves utilizing one of the robot's motion axes to drive a dispensing pump mounted to the robot's end effector. This motion axis is sometimes referred to as the sixth axis of control. However, this application limits the motion of the robotic manipulator because only five of the typical six axes of motion are available. As a result, the robot manipulator is limited to applying sealant to a surface lying completely in a single dimensional plane. Thus, the functionality of this robotic manipulator design is severely limited for applications having a surface lying in two or more dimensional planes.
In addition, more complex hardware is required for supporting the sealant dispenser because it is always in motion with the end effector of the robotic manipulator. A substantial amount of weight is also placed on the robot end effector which can lead to uneven or inconsistent movement of the robotic manipulator. This inconsistent movement translates into error, which then reduces the benefits of using a high precision robot for the manufacturing task.
To achieve maximum flexibility in the manufacturing environment, it is desirable that the robot manipulator utilize all six axes of motion so that the end effector can be moved into any desired position. It is also desirable to remove the sealant dispenser from the robot manipulator, and mount the sealant dispenser in a fixed location. This in turn would remove a substantial amount of weight from the end effector of the robot, and increase the accuracy of the robot's movements. According to this envisioned design, the robotic manipulator can be used for moving parts to which sealant is to be applied about or underneath the fixed location sealant dispenser. Finally, it is desirable to operate the sealant dispenser with a feedback controlled servo mechanism for increasing the precision of the sealant application process.